Hammerhead sharks swim in a school underwater at Wolf Island in the Galapagos archipelago. The hammerheads eyes and other sensor organs are placed far apart on its wide head to give the shark greater ability to sense the location of prey.
Image ID: 16271
Species: Scalloped hammerhead shark, Sphyrna lewini
Location: Wolf Island, Galapagos Islands, Ecuador

A brown pelican preening, reaching with its beak to the uropygial gland (preen gland) near the base of its tail. Preen oil from the uropygial gland is spread by the pelican's beak and back of its head to all other feathers on the pelican, helping to keep them water resistant and dry.
Image ID: 30326
Species: Brown Pelican, Pelecanus occidentalis, Pelecanus occidentalis californicus
Location: La Jolla, California, USA

Blue whale skeleton in Antarctica, on the shore at Port Lockroy, Antarctica. This skeleton is composed primarily of blue whale bones, but there are believed to be bones of other baleen whales included in the skeleton as well.
Image ID: 25604
Species: Blue whale, Balaenoptera musculus
Location: Port Lockroy, Antarctic Peninsula, Antarctica

Humpback whale lunge feeding on Antarctic krill, with mouth open and baleen visible. The humbpack's throat grooves are seen as its pleated throat becomes fully distended as the whale fills its mouth with krill and water. The water will be pushed out, while the baleen strains and retains the small krill.
Image ID: 25648
Species: Humpback whale, Megaptera novaeangliae
Location: Gerlache Strait, Antarctic Peninsula, Antarctica

Bryozoan grows on a red gorgonian on rocky reef, below kelp forest, underwater. The red gorgonian is a filter-feeding temperate colonial species that lives on the rocky bottom at depths between 50 to 200 feet deep. Gorgonians are oriented at right angles to prevailing water currents to capture plankton drifting by.
Image ID: 25395
Species: Red gorgonian, Lophogorgia chilensis
Location: San Clemente Island, California, USA